The Supreme Court’s conflicting Fourth Amendment interpretations.

Entry 6: The two Fourth Amendments.

The Supreme Court appears to be moving in opposite directions with regard to two strands of Fourth Amendment jurisprudence.

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Dahlia, Walter, Dawn, Akhil, Dick,

You must excuse me if I’m a bit frazzled right now; I’ve suffered a bad case of Fourth Amendment whiplash this week. First, on Monday, the Supreme Court handed down Utah v. Strieff—a terrible decision that creates a large and (in my opinion) totally unwarranted loophole in the exclusionary rule, which is meant to prevent the introduction of illegally obtained evidence at trial. Then, on Thursday, the same court announced its decision in Birchfield v. North Dakota, holding, by a 7–1 vote, that warrantless blood tests of suspected drunk drivers are unconstitutional. A crushing blow for the Fourth Amendment, followed by a resounding victory. What gives?

One answer is that the court is moving in opposite directions with regard to two strands of Fourth Amendment jurisprudence: the exclusionary rule, and searches incident to arrest. Strieff involved the former, which requires the suppression of evidence obtained from an illegal search or seizure. The four conservatives don’t much like the exclusionary rule, and by coaxing Justice Stephen Breyer to their bloc, they were able to use Strieff as a vehicle to weaken it yet again. Under Justice Clarence Thomas’ majority opinion, evidence obtained after an illegal stop may now be introduced at trial ifthe officer discovers an arrest warrant following the stop.

Huh? As Justice Sonia Sotomayor pointed out in her strikingly personal and empathetic dissent, that creates a perverse incentive for officers to stop anyone they want—knowing that, if they thendiscover an arrest warrant, the stop will be legitimized. That undermines a key purpose of the exclusionary rule, which is to discourage police overreach. As Sotomayor ominously summarizes the ruling: “This case allows the police to stop you on the street, demand your identification, and check it for outstanding traffic warrants—even if you are doing nothing wrong.”

Birchfield, in contrast, feels like the decision of an entirely different court—even though four of the justices who voted for the cops in Strieff also joined the Birchfield majority. The case involves “implied consent” laws against drunk driving. These laws declare that, by driving on a state’s roads, you consent to let law enforcement determine your blood-alcohol level. That includes consenting to actual blood tests—which, the court helpfully explains, “require piercing the skin” with a needle and drawing the suspect’s blood. If you refuse, under these statutes you may be fined and imprisoned.

In a decision by Justice Samuel Alito—who almost never sides with the defendant in Fourth Amendment cases—the court held that this implied consent scheme is unconstitutional with regard to blood tests. Drawing blood, Alito wrote, is a “search” under the Fourth Amendment. Police are permitted to conduct warrantless searches upon arrest if they promote “legitimate government interests” without intruding too extensively upon individual privacy. Blood tests, Alito held, severely intrudes upon an individual’s “human dignity and privacy” and “impinge on … sensitive interests.” Thus, officers who wish to determine blood-alcohol level from a driver’s blood sample must generally get a warrant first. The court actually arrived at this conclusion several terms ago, but Birchfield explicitly states that implied consent laws aren’t a valid workaround.

By contrast, the Birchfield majority signed off on warrantless breathtests. These tests, Alito wrote, are still “searches” under the Fourth Amendment—but they don’t require a warrant because they present “a minimum of inconvenience” and are less intrusive than blood tests. As that baby-splitting outcome suggests, the decision was a perfectly middle-of-the-road resolution. Sotomayor and Justice Ruth Bader Ginsburg would have required a warrant for both blood and breath tests; Thomas argued that a warrant isn’t required for either.

Taken together, Strieff and Birchfield tell the tale of two different Fourth Amendments. One—call it the progressive Fourth Amendment—focuses on deterring police from acting on their (possibly unconscious) biases and takes a realist view of the outsized impact that police misconduct has on minority and low-income communities. The other—call it the conservative Fourth Amendment—focuses on hardline rules to prevent police overreach in a well-defined but limited set of circumstances. It’s often said that you win a Fourth Amendment case by convincing the justices that the search in question could affect them. That’s the conservative Fourth Amendment at work, and it may well have guided the resolution of Birchfield. After all, everyone with a driver’s license can envision the horror of getting pulled over for sloppily changing lanes—then facing the unenviable choice of a blood test or jail time.

As for Strieff? Well, not everyone can imagine leaving a drug house with methamphetamine on your person, as Edward Strieff did when he was stopped. (The officer who detained him didn’t know any of that at the time, of course.) Sotomayor, however, understands that Strieff wasn’t just about one meth head. It was about police power and the authority of law enforcement to justify prejudiced and pretextual stops that, in aggregate, oppress and victimize minority communities. “This case tells everyone, white and black, guilty and innocent,” Sotomayor wrote in dissent, that “you are not a citizen of a democracy but the subject of a carceral state, just waiting to be cataloged. We must not pretend that the countless people who are routinely targeted by police are ‘isolated.’ … They are the ones who recognize that unlawful police stops corrode all our civil liberties and threaten all our lives.”

Or maybe I’m just grasping for theories to explain the weird divergence we’ve seen this week. Perhaps a simpler explanation is that Breyer—whose obsession with “workable” constitutional rules often leads him to swing right on searches and seizures, since the most pragmatic solution typically favors law enforcement—joined the conservatives to create a majority in Strieff for that reason, and there’s your ruling.

I’m especially interested to hear what you think, Dick and Akhil. Dick, you’ve called the Supreme Court’s warrant requirement “ahistorical”; does Birchfield take it too far? And Akhil, you don’t accept the constitutional validity of the exclusionary rule at all. Does Strieff seem like a step in the right direction to you?